Numerous attempts have been made in the past to provide a suitable cover for normally open top freight cars employed in the transporting of various granular materials such as coal, grains and the like. Such covers have been in the nature of hinged cover plates extending across the top of the car, the cover being constructed of wood, metal and various other type materials. In some instances a cover constructed of a fabric such as canvas has been utilized in this invironment but where a fabric cover has been employed in the past some problems have been presented particularly in providing a suitable means for securing the cover to the top of the car. Canvas covers have not proved to be desirable. The cost of canvas covers is prohibitive and often such covers are removed from the cars when the car reaches its destination and not returned to the shipper thus adding to the costs of shipping the materials in a car which has been provided with a canvas cover. Also, in the past, elaborate means have been devised to secure the cover to the sides and ends of the freight car thus adding to the costs of using a canvas cover for the car.
With the above in mind, it is one object of the invention to provide a simple yet efficient clamp means for securing a cover of sheet material to the top of a normally open topped freight car.
Another object of the invention is to provide a means whereby the cover of sheet material is caused to follow the contour of the materials within the car body thus insuring a constant contact of the cover with the materials in the car body.
Another object of the invention is to provide a means whereby the cover extending over the extension at the forward and rear portion of the car body will be securely fastened to the extension and thus avoiding an accidental removal of the cover at these portions of the freight car.
To the accomplishment of the above and subordinate objects presently appearing, a preferred embodiment of our invention has been illustrated in the accompanying drawings and set forth in detail in the succeeding description, and defined in the claims appended hereto.